1. Field of the Invention
The present invention relates to a device for dispensing a fluid or a powder, and more particularly it relates to such a device provided with means enabling it to be used at a determined distance from the location to be treated.
2. Description of the Relate Art
A mechanically-actuated device for spraying or dispensing a fluid is known from document FR-2 682 305. In that device, a pump is cocked by means of an actuator spring, the device including spring-locking means, trigger means, and a cap for protecting the housing and provided with means for re-cocking the device, which means become operative while said cap is being closed.
Because it is triggered independently of the user, that prior device operates in satisfactory manner, in particular by guaranteeing that reproducible quantities are dispensed, however it does not make it possible to comply with certain requirements that can arise as a function of the type of substance to be dispensed and the type of use to which the device is put.
Thus, for certain substances, e.g. substances for systemic use such as hormone replacement therapy, the area to be sprayed must be defined as accurately as possible in order to make bioavailability reproducible. In particular, for transdermal use, it is important to distribute the sprayed liquid over an area that is predetermined, reproducible, and uniform, in order to favor reproducible absorption by the skin.
Also, in ophthalmological use, in order to promote compliance, it is important to ensure that the substance, e.g. a drop of liquid, reaches the eye under the same dynamic conditions.
In addition, for pulmonary use, in order to reduce side-effects, it can sometimes be important to ensure that sprayed particles of small size only are breathed in by the patient, and to avoid any large particles (which cannot be inhaled because of their size) becoming deposited in the patient's mouth, where they could generate undesirable effects, such as candidosis, for example. For this purpose, it is necessary to spray from a distance that is large enough to ensure that heavy large particles do not reach the mouth, while being small enough to ensure that small particles are breathed in.